Process for the manufacture of tubes and rods of sheet wood



Patented Jan. 12, 1943 UNITED STATES PROCESS FOR THE MANUFACTURE OF TUBES AND RODS F SHEET WOOD Giuseppe Moschetto, Turin, Italy; vested in the Alien Property Custodian No Drawing. Application April 30, 1941, Serial No. 391,223. In Italy May 21, 1940 Claims.

This invention relates to a process for manufacturing tubes of high resistance from rolled wood sheets. Said tubes may be used for conveying steam, gas, water, combustible or lubricating liquids or as parts of constructions, such as latticework, fences and parts of machines and apparatus. The tube or rod is preferably constituted by two three or more superposed Wood sheets or ply wood. The sheets are impregnated with a gluing solution such as albumine glue, or a suitable resin, for instance urea-formaldehyde. or suitable cements, in such manner as to fill completely the cells.

While the gluing solution is in the wet state, the sheets are rolled on a core and tightly bound thereon. These rollers are then dried in an autoclave under a pressure of -50 at. at a temperature of about 105 C. The dried tube is subsequently drawn from the core, dipped in the said bath of glue, resin or cement, dried in hot air, then dipped in an insolubilising bath for instance in a formaldehyde or sodium bichromate bath, if a glue bath is employed, and again dried in hot air. It is then again dipped in the said glue, resin or cement bath and dried in hot air. The tube thus obtained is finally dried at about C. and if required by its particular use, dipped in a bath for instance of sodium or potassium silicate or a mixture thereof to make it non-inflammable.

The wood tube thus prepared has a higher mechanical resistance than the original wood and can withstand inner pressures and high temperatures and serve as parts of mechanical constructions, for instance bicycles, carriage bodies, aircraft and the like. It may be of a section other than circular when required by its particular use. The tube may of course be varnishecl, polished, coated and may generally undergo various additional treatments according to the desired purpose.

In certain cases it may be advantageous to use instead of the mandrel or core a tube which will remain incorporated in the outer coating constltuted by the sheets of wood rolled on said inner tube. The inner tube may be of any suitable material, such as wood, paper, cloth, cement, metal, and the like previously coated, if necessary, with a thin sheet of tin, aluminium or other material conferring particular properties to the final product.

The tubes according to this invention may be connected together by means of ordinary connecting pieces or rubber, aluminium and the like connecting pieces.

\Vhat I claim is:

1. A process for manufacturing rods and tubes of sheet wood, consisting in dipping the sheets in a bath of a gluing solution filling its cells, rolling said sheets in the form of a tube, drying the roller thus formed in an autoclave under a pressure of 20-50 at. at a temperature of about C., dipping again the roller in said bath of gluing solution and then drying it in hot air, thus obtaining a stifi tube, dipping said tube in an insolubilising bath, then dry the tube in hot air and dipping again the dried tube made insoluble in the said bath of gluing solution and finally drying said tube at about 35 C.

2. A process for manufacturing rods and tubes of sheet Wood, consisting in dipping the sheets in a bath of a gluing solution filling its cells, rolling said sheets in the form of a tube, drying the roller thus formed in an autoclave under a pressure of 20-50 at. at a temperature of about 105 C., dipping again the roller in the said bath of gluing solution and then drying it in hot air, thus obtaining a stiff tube, dipping said tube in an insolubilising bath, then drying the tube in hot air and dipping again the dried tube made insoluble in the said bath of gluing solution and drying said tube at about 35 C., subsequently dipping the tube in a bath to make it noninflammable and then finally drying it at about 35 C.

3. A process for manufacturing tubes of sheet wood, consisting in dipping said sheets in a bath of gluing solution filling its cells, rolling said impregnated sheets on a tube of any material, such as wood, paper, cloth, cement, metal, drying the roller thus formed together with the tube in an autoclave under a pressure of 20-25 at. at a temperature of about 105 C., dipping again the roller and tube in the gluing solution and drying it in hot air thus obtaining a stiff tube, dipping said tube in an insolubilising bath, then dry the tube in hot air and dipping the dried tube made insoluble in the gluing solution and finally dry said tube at about 35 C.

4. A process for manufacturing tubes of sheet wood, consisting in dipping said sheets in a bath of gluing solution filling its cells, rolling said impregnated sheets on a tube of any material, such as wood, paper, cloth, cement, metal, drying the roller thus formed together with the tube in an autoclave under a pressure of 20-25 at. at a temperature of about 105 0., dipping again the roller and tube in the gluing solution and drying it in hot air thus obtaining a still tube, dipping said tube in an insolubilising bath, then dry the tube in hot air and dipping the dried tube made insoluble in the gluing solution, drying and subsequently dipping the tube in a bath adapted to make it non-inflammable and finally drying the tube at about 35 C.

5. A process as claimed in claim 4, in which the inner tube on which the wood sheets are rolled, is previously coated with a thin sheet of a material adapted to confer to the final product particular properties, such as tin, aluminium or the like sheets.

G'IUSEPPE MOSCl-IETTO. 

